Locking and positioning devices are used to lock and unlock movement of a first member relative to a second member to allow positioning or repositioning therebetween. For example, locking devices are known which lock along a single axis. U.S. Pat. No. 3,885,764 to Pabreza describes one such locking and positioning device which locks vertical motion along a vertical axis. The Pabreza device has applicability to height adjustments of chairs. The locking action in the Pabreza device also locks angular rotation about that same vertical axis. The adjustment is accomplished by actuation of a cam and lever device. U.S. Pat. No. 2,042,443 to Buckstone describes another mechanism for locking vertical motion which requires a separate and independent device for locking rotary motions of brackets F and G. Tripods are an additional example of devices which generally have a locking mechanism for each degree of freedom. U.S. Pat. No. 5,056,863 to DeKraker et al. illustrates a method of lateral adjustment of an armrest. U.S. Pat. No. 3,861,815 to Landaeus describes a device for releasably mounting a hub or a wheel onto a shaft. None of these aforementioned devices can lock and allow adjustment of greater than two degrees of freedom with the action of a singular actuation device.